Basis Of Presentation (Effect On Consolidated Condensed Statements Of Changes In Stockholders' Equity) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Retained earnings, December 31, 2010			$ 406,342
Net income	28,953	21,166	51,149	41,945
Total comprehensive income			42,842
Retained earnings, June 30, 2011	425,679		425,679
As Previously Reported [Member]
Retained earnings, December 31, 2010			422,458
Net income	20,317		41,695
Total comprehensive income			33,388
Retained earnings, June 30, 2011	432,341		432,341
Effect Of Change [Member]
Retained earnings, December 31, 2010			(16,116)
Net income	8,636		9,454
Total comprehensive income			9,454
Retained earnings, June 30, 2011	$ (6,662)		$ (6,662)